Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60G—VEHICLE SUSPENSION ARRANGEMENTS
  • B60G17/00—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load
  • B60G17/015—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load the regulating means comprising electric or electronic elements
  • B60G17/018—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load the regulating means comprising electric or electronic elements characterised by the use of a specific signal treatment or control method
  • B60G17/0185—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load the regulating means comprising electric or electronic elements characterised by the use of a specific signal treatment or control method for failure detection
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60G—VEHICLE SUSPENSION ARRANGEMENTS
  • B60G2400/00—Indexing codes relating to detected, measured or calculated conditions or factors
  • B60G2400/60—Load

Definitions

• the invention relates to a system for monitoring the driving state of a vehicle with a sensor system measuring the wheel force for determining a wheel force on at least one wheel of the vehicle and means for processing the determined wheel force.
• the invention further relates to a method for monitoring the driving state of a vehicle, comprising the steps of: determining a wheel force on at least one wheel of the vehicle by means of a sensor system measuring the wheel force and processing the determined wheel force.
• the generic system and the generic method are used in the context of vehicle dynamics controls. For example, they are used in connection with anti-lock braking systems (ABS), traction control systems (ASR) and the electronic stability program (ESP). It is known to detect the wheel speeds of the individual wheels of a motor vehicle via sensors and the detected wheel speeds in the control and / or regulation of the driving behavior of the Motor vehicle to be considered. Although good results have already been achieved with the known methods and systems, there is an interest, particularly with regard to traffic safety, in further improving the generic methods and systems.
• ABS anti-lock braking systems
• ASR traction control systems
• ESP electronic stability program
• tires can be provided in which magnetized surfaces or strips are incorporated into each tire, preferably with field lines running in the circumferential direction. For example, the magnetization always takes place in sections in the same direction, but with the opposite orientation, that is to say with alternating polarity.
• the magnetized stripes preferably run near the rim flange and near the mountain. The sensors therefore rotate at wheel speed.
• Corresponding sensors are preferably attached to the body at two or more points that are different in the direction of rotation and also have a different radial distance from the axis of rotation. As a result, an inner measurement signal and an outer measurement signal can be obtained. A rotation of the tire can then via the changing polarity of the measurement signal or of the measurement signals are detected in the circumferential direction. The wheel speed can be calculated, for example, from the scope of the roll and the change over time of the inner measurement signal and the outer measurement signal.
• the sensors can be implemented as micro sensors in the form of microswitch arrays.
• forces and accelerations and the speed of a wheel are measured by the sensors arranged on the movable part of the wheel bearing. This data is compared with electronically stored basic patterns or with data from a similar or similar microsensor that is attached to the fixed part of the wheel bearing.
• the invention is based on the generic system in that a state of a shock absorber assigned to the wheel can be determined from a result of the processing.
• critical driving situations can occur in the event of strong decelerations, in particular on simple routes or even during normal driving, for example when cornering. Cornering on poor road surfaces can be particularly critical.
• the critical situations arise because, for example, the chassis vibrates due to an interference force is offset and this vibration can not be brought to decay by the shock absorbers.
• An interference force can be generated, for example, by uneven driving or an initiated braking torque. In these cases, the frictional connection between the tire and the road can be lost, which can result in critical driving situations.
• the loss of a damper function can be recognized at an early stage, which ultimately increases driving safety.
• a sensor system that measures the wheel force is suitable for the purpose of monitoring the chassis damping, since it can be used to measure the wheel contact force. If there are vibrations of the chassis influenced by a disturbing torque, the vertical chassis movement and thus the measured contact force are modulated.
• the sensor system measuring the wheel force has tire sensors.
• the tire sensors described in connection with the prior art are particularly suitable for measuring, for example, the wheel contact force, so that driving safety can be improved to a great extent.
• the sensor system that measures the wheel force can also be useful for the sensor system that measures the wheel force to have wheel bearing sensors.
• wheel contact forces can also be measured with such wheel bearing sensors, so that the system according to the invention can also be implemented in this way.
• the system according to the invention shows its particular advantages in that the force amplitude of an interference force can be determined by determining the wheel force, whereby a shock absorber is set in motion by the interference force, and that vibration damping can be determined by determining at least one subsequent amplitude of the vibration Vibration damping can be evaluated and that the state of the shock absorber can be determined depending on the evaluation.
• a disturbing torque for example when a vehicle brakes heavily or due to road surface disturbances, causes the vehicle to vibrate.
• An intact damper unit quickly subsides the vibration. If damping is disturbed in its function, the vibration persists over a period of time that is not justifiable in connection with driving safety.
• a characteristic value for the vibration damping can be determined and evaluated by measuring at least one following amplitude. It is also conceivable that the primary force amplitude, which is generated by the interference force, is not used as the starting value for the comparison of the force amplitudes. Rather, any successive force amplitudes can be used as a measure of the damping.
• the invention is developed in a particularly preferred manner in that the vibration damping is assessed by comparison with a predetermined critical vibration damping. Such predetermined critical vibration damping is generally vehicle-specific and can be represented by a "critical damping constant".
• a current damping constant can be determined and compared with the vehicle-specific critical damping constant. From this comparison, insufficient damping can then be recognized if necessary, namely if the current damping constant is smaller than the critical damping constant.
• vibration damping it is also possible for the vibration damping to be assessed by measuring the temporal change in successive vibration amplitudes. This percentage decrease can also be a measure of sufficient or insufficient damping, so that countermeasures can ultimately be taken.
• the system according to the invention is developed in a particularly advantageous manner in that a display can be triggered depending on the determined state of the shock absorber.
• a display can be implemented in a passenger car, for example, via a display in the interior, so that the driver is informed in good time about inadequate damping and thus about impending critical driving situations.
• the invention builds on the generic method in that a state of a shock absorber assigned to the wheel is determined from a result of the processing.
• a state of a shock absorber assigned to the wheel is determined from a result of the processing.
• the loss of a damper function can be recognized at an early stage, which ultimately increases driving safety.
• a sensor system that measures the wheel force is suitable for the purpose of monitoring the chassis damping, since it can be used to measure the wheel contact force. If there are vibrations of the chassis influenced by a disturbing torque, the vertical chassis movement and thus the measured contact force are modulated.
• the sensor system measuring the wheel force uses tire sensors.
• the tire sensors described in connection with the prior art are particularly suitable for measuring, for example, the wheel contact force, so that driving safety can be improved to a great extent.
• the sensor system measuring the wheel force uses wheel bearing sensors. With such wheel bearing sensors, for example, wheel riot forces are measured, so that the method according to the invention can also be implemented in this way.
• the method according to the invention shows its particular advantages in that the force amplitude of a disturbing force is determined by determining the wheel force, a shock absorber being set in vibration by the disturbing force, that a vibration damping is determined by determining at least one subsequent amplitude of the vibration, that the vibration damping is evaluated and that the state of the shock absorber is determined as a function of the evaluation.
• a disturbing torque for example when a vehicle brakes heavily or due to road surface disturbances, causes the vehicle to vibrate.
• An intact damper unit quickly subsides the vibration. If damping is disturbed in its function, the vibration persists over a period of time that is not justifiable in connection with driving safety.
• a characteristic value for the vibration damping can be determined and evaluated by measuring at least one subsequent amplitude. It is also conceivable that the primary force amplitude, which is generated by the interference force, is not used as the starting value for the comparison of the force amplitudes. Rather, any successive force amplitudes can be used as a measure of the damping.
• the invention is developed in a particularly preferred manner in that the vibration damping is assessed by comparison with a predetermined critical vibration damping. Such a predetermined critical vibration damping is generally vehicle-specific and can be represented by a "critical damping constant".
• a current damping constant can be determined and compared with the vehicle-specific critical damping constant. From this comparison, insufficient damping can then be recognized if necessary, namely if the current damping constant is smaller than the critical damping constant.
• vibration damping it is also possible for the vibration damping to be assessed by measuring the temporal change in successive vibration amplitudes. This percentage decrease can also be a measure of sufficient or insufficient damping, so that countermeasures can ultimately be taken.
• the method according to the invention is developed in a particularly advantageous manner in that a display can be triggered as a function of the determined state of the shock absorber.
• a display can be implemented in a passenger car, for example, via a display in the interior, so that the driver is informed in good time about inadequate damping and thus about impending critical driving situations.
• a start prevention can be activated depending on the determined state of the shock absorber.
• the invention is based on the knowledge that the damper monitoring based on the wheel force makes it possible to determine defects or worn dampers at an early stage and to reduce dangerous driving situations. It is conceivable that the system according to the invention carries out continuous monitoring. Also, the system can be 'designed so that it is activated only by introducing a relatively large disturbance force, disgust, for example, a pothole or a Schachtde- because of large disturbing forces particularly reliable measurement results can be achieved.
• FIG. 1 shows a block diagram of a system according to the invention
• FIG. 2 shows a flow diagram of a method according to the invention
• FIG. 3 shows a part of a tire equipped with a tire sidewall sensor
• FIG. 4 shows exemplary signal profiles of the tire side wall sensor shown in FIG. 3.
• FIG. 1 shows a block diagram of a system according to the invention.
• Wheel forces of a wheel 12 are determined by means of a sensor system 10 measuring the wheel force.
• the wheel 12 shown is representative of several wheels of a vehicle, in particular a motor vehicle.
• the sensor system 10 measuring the wheel force is connected to a device 14 for determining vibration damping.
• the device 14 for determining the vibration damping is coupled to a device IS for evaluating the vibration damping.
• the device 16 for evaluating the vibration damping is connected to a display device 18.
• the sensor system 10 measuring the wheel force can be part of a side wall sensor, for example. It can also be provided that the sensor system 10 is designed as a wheel bearing sensor system. Among other things, the sensor system 10 measures the tire's contact force.
• the vibration damping is determined in the unit 14 from the signals output by the sensor system 10 to the device 14. This determination can be made, for example, by measuring successive vibration amplitudes after the conduct an interference force.
• the vibration damping thus determined in the device 14 is fed to the device 16 for evaluating the vibration damping.
• the vibration damping can be evaluated, for example, by comparing a determined damping constant with a critical damping constant specific to the vehicle. It is also conceivable that the percentage decrease in successive amplitudes is evaluated.
• a display device 18 is then activated. This can be provided, for example, in the interior of a vehicle and emit a warning if the vibration damping determined is less than a critical vibration damping value and was therefore rated as a critical value in the device 16. As an alternative or in addition to the alarm device 18, a start prevention can also be provided, which prevents the vehicle from starting in the case of critical vibration damping values.
• FIG. 2 shows a flow diagram of a method according to the invention. First, the meaning of the individual process steps is given:
• SOI measure a wheel force.
• S02 Determine a circuit damping.
• S03 Vibration damping greater than predetermined vibration damping?
• a wheel force is measured in step S01, for example the contact force of a wheel.
• vibration damping is determined from the results of step SOI. This can be done by comparing successive wheel force amplitudes.
• step S03 the vibration damping determined is compared with a predetermined vibration damping. ACTUAL: If the vibration damping determined is greater than a predetermined vibration damping, this is classified as unproblematic and the process sequence can continue with the normal monitoring operation.
• an alarm is output, for example, in step S04. It is also possible to activate a start prevention.
• FIG. 3 shows a section of a tire 32 with a tire / side wall sensor system 20, 22, 24, 26, 28, 30.
• This comprises two sensors 20, 22, which are attached to the body at two different points in the direction of rotation. Furthermore, the sensors 20, 22 have different radial distances from the axis of rotation of the wheel.
• the sidewall of the tire 32 is provided with a plurality of sensors 24, 26, 28, 30, which have alternating magnetic polarity.
• FIG. 4 shows the signal profiles S. and S a of the sensor 20 arranged on the inside according to FIG. 3 and of the sensor 22 arranged outside according to FIG. 3.
• a rotation of the Tires are recognized by the changing polarity of the measurement signals.
• the wheel speed for example , can be calculated therefrom from the rolling range of the temporal change in the signals S. and S a .
• Torsions of the tire can be determined by means of phase shifts between the signals and thus, for example, wheel forces can be measured directly.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Vehicle Body Suspensions (AREA)
• Force Measurement Appropriate To Specific Purposes (AREA)
• Vibration Prevention Devices (AREA)
• Fluid-Damping Devices (AREA)

Applications Claiming Priority (5)

Publications (1)

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ID=26008126

Family Applications (1)

Country Status (4)

Families Citing this family (8)

Family Cites Families (9)

• 2001
  • 2001-12-22 EP EP01991680A patent/EP1347884A1/de not_active Withdrawn
  • 2001-12-22 WO PCT/DE2001/004907 patent/WO2002053397A1/de not_active Application Discontinuation
  • 2001-12-22 JP JP2002554530A patent/JP2004517278A/ja not_active Withdrawn
  • 2001-12-22 US US10/220,641 patent/US20040148074A1/en not_active Abandoned

Non-Patent Citations (1)

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